1. Technical Field
The present invention relates to a color correction coefficient generator, a color correction coefficient generation method and a computer readable medium storing a program.
2. Related Art
Recent widespread of color devices such as digital cameras, color scanners, color printers and color displays has boosted a market demand for colors. This demand is especially high for systems used in desk top publishing (DTP) and the like. A color management system (CMS) is indispensable for devices of such systems, and a device calibration technique has been developed for achievement of stable color reproduction in devices. So far, such color correction has been preformed on the basis of a color profile, typically an ICC profile, or the like. Specifically, a coefficient for each grid point in a look-up table (LUT) for color correction is firstly determined, and then color correction is performed in any of various types of already-invented interpolation processing or the like using the coefficient.
Most of the color correction methods for the device calibration techniques are currently based on a one-dimensional LUT. For such calibration, there are two main types of calibration techniques, one of which is for primary color calibration for correcting primary colors, and the other of which is for gray balance calibration for correcting a process black that is a mixture of three colors of cyan (C), magenta (M), and yellow (Y) In other words, the techniques for tone reproduction curve (TRC) type calibration have been already developed.
However, such TRC type calibration has limitation as this technique capable of correcting only a certain part of colors. For example, as for the primary color calibration, only a part consisting of any primary color is a correction target and sufficiently-high correction accuracy is not guaranteed for a part consisting of mixed colors such as a secondary color or tertiary color. As for the gray balance calibration, only a part of a process gray that is the mixture of three colors is to be corrected, and achievement of sufficiently-high correction accuracy is not guaranteed for a part of colors other than the process gray.